To illustrate the generality and feasibility of the proposed design method, we present two high-performance compact systems as design examples. https://www.selleckchem.com/products/8-bromo-camp.html Both systems meet the design requirements, with small distortions after optimization. Their modulation transfer function (MTF) curves are close to the diffraction limit. This design framework can be used to design next-generation imaging systems using phase elements for applications including near-eye-displays, high-performance cameras and remote sensing and detection. The proposed method also offers insight into design of imaging systems that are constrained to conformal substrate shapes or integrated substrates.A highly sensitive method for detecting transient reflection in the extreme ultraviolet (XUV) region was developed on the basis of high-order harmonics for tracking carrier and coherent phonon dynamics. The use of lock-in detection and boxcar integration enables us to observe optical modulation (ΔR/R) as high as 1?×?10-4, and the data acquisition takes only four minutes. XUV transient reflections of bismuth exhibited exponential decay originating from excited carriers and periodic oscillation originating from A1g optical phonons. The linear power dependence of the electronic and phonon amplitudes indicated that one-photon excitation occurred under the experimental conditions. The cosine of the initial phase of the phonon oscillation revealed that a displacive excitation mechanism contributed to phonon generation. The phonon parameters obtained by the XUV and NIR probes were consistent even though their penetration depths were different. The result indicated that the XUV and NIR pulses probe the same excited region, which should be near the surface due to the short penetration depth of the NIR pump pulses. The present highly sensitive means of detecting XUV transient reflections in solid-state materials could be utilized for detecting attosecond dynamics in the future.We report the design and operation of a surface-emitting surface acoustic wave (SAW) acousto-optical modulator which behaves as a cm-scale linear hologram in response to an applied electronic waveform. The modulator is formed by an optical waveguide, transducer, and out-coupling surface grating on a 1 mm-thick lithium niobate substrate. We demonstrate the ability to load and illuminate a 9-region linear hologram into the modulator's 8 mm-long interaction region using applied waveforms of 280-320 MHz. To the best of the authors' knowledge, this is the first demonstration of a monolithically-integrated, surface-emitting SAW modulator fabricated using lithographic techniques. Applications include practical implementations of a holographic display.We present the design, simulation, and experimental demonstration of a Si-GST grating assisted contra-directional coupler for optical switching. The effective refractive index of the GST-loaded silicon waveguide changes significantly when the GST is switched from the amorphous state to the crystalline state, allowing for large tuning of the propagation constant. The two coupled waveguides are designed to satisfy the phase-match condition only at the amorphous state to achieve Bragg reflection at the drop-port. Experimental results show that the device insertion loss is less than 5 dB and the extinction ratio is more than 15 dB with an operation bandwidth of 2.2 nm around the 1576 nm operating wavelength. Due to the nonvolatile property of GST, there is no static power consumption to maintain the two states. It is the first demonstration of a GST-enabled grating coupler that can be switched by phase change material.We propose a photonic spiking neural network (SNN) based on excitable vertical-cavity surface-emitting lasers with an embedded saturable absorber (VCSELs-SA) for emulating the sound azimuth detection function of the brain for the first time. Here, the spike encoding and response properties based on the excitability of VCSELs-SA are employed, and the difference between spike timings of two postsynaptic neurons serves as an indication of sound azimuth. Furthermore, the weight matrix contributing to the successful sound azimuth detection is carefully identified, and the effect of the time interval between two presynaptic spikes is considered. It is found that the weight range that can achieve sound azimuth detection decreases gradually with the increase of the time interval between the sound arriving at the left and right ears. Besides, the effective detection range of the time interval between two presynaptic spikes is also identified, which is similar to that of the biological auditory system, but with a much higher resolution which is at the nanosecond time scale. We further discuss the effect of device variations on the photonic sound azimuth detection. Hence, this photonic SNN is biologically plausible, which has comparable low energy consumption and higher resolution compared with the biological system. This work is valuable for brain-inspired information processing and a promising foundation for more complex spiking information processing implemented by photonic neuromorphic computing systems.Indium Tin Oxide nanowire arrays (ITO-NWAs), as epsilon-near-zero (ENZ) materials, exhibit a fast response time and a low saturable absorption intensity, which make them promising photoelectric materials. In this study, ITO-NWAs were successfully fabricated using a chemical vapor deposition (CVD) method, and the saturable absorption properties of this material were characterized in the near-infrared region. Further, passively Q-switched all-solid-state lasers were realized at wavelengths of 1.0, 1.3, and 2.0 ?m using the as-prepared saturable absorber (SA). To the best of our knowledge, we present the first application of ITO-NWAs in all-solid-state lasers. The results reveal that ITO-NWAs may be applied as an SA while developing Q-switched lasers and that they exhibit a broad application prospect as broadband saturable absorption materials.Optically resonant high-index dielectric metasurfaces featuring Mie-type electric and magnetic resonances are usually fabricated by means of planar technologies, which limit the degrees of freedom in tunability and scalability of the fabricated systems. Therefore, we propose a complimentary post-processing technique based on ultrashort (? 10&nbsp;ps) laser pulses. The process involves thermal effects crystallization and reshaping, while the heat is localized by a high-precision positioning of the focused laser beam. Moreover, for the first time, the resonant behavior of dielectric metasurface elements is exploited to engineer a specific absorption profile, which leads to a spatially-selective heating and a customized modification. Such technique has the potential to reduce the complexity in the fabrication of non-uniform metasurface-based optical elements. Two distinct cases, a spatial pixelation of a large-scale metasurface and a height modification of metasurface elements, are explicitly demonstrated.